1. Field of the Invention
This invention relates to a multi-pin terminal adapter for electrical connection to printed circuit boards and associated electronic parts. The invention is also directed to the combination of such an adapter with a relay socket for deriving from and adding an electrical signal to an integrated circuit and a printed circuit board.
2. Prior Art
Generally, printed circuit boards are provided with a large number of leads connected to densely packed electronic circuit elements such as resistors and capacitors as in integrated circuits. The leads are however broadly standardized under common specifications related to configuration, lead-to-lead spacing (pitch) and other design parameters so as to provide facilitated circuit assembly and enhanced productivity.
For purposes of illustration, a typical form of conventional flat-package integrated circuit is shown in FIGS. 4a and 4b, incorporating a total of 64 contact pins known as "Gull Wing" extending in a closely aligned row downwardly symmetrically from four sides of a rectangular substrate for solder connection to corresponding leads on an underlying printed circuit board which is not shown.
The design and development work on printed circuit boards would be held in abeyance pending the outcome of newly developed circuit components of a high packing density. This procedure is literally time-consuming. It is therefore desirable to carry out the development project of circuit component parts simultaneously or parallel with the design of related circuit boards, in which instance numerous signal leads are connected to extremely clouded terminal lands disposed on the printed circuit board which represent the prospective positions for mounting high-density circuit components, the signal leads being then connected to an external equivalent electronic circuitry for simulation or other testing. With such densely packed integrated circuits (IC), it has been extremely difficult, if not impossible, to locate the correct contact pin or pins for input of a predetermined signal particularly where the IC circuit is mounted closely adjacent to other circuit components, often resulting in damaged or otherwise defective ICs. Sockets have been proposed to protect costly ICs against objectionable mechanical/electrical stresses during the stage of preparation of associated printed circuit boards. However, the design of such protective sockets would not envision the compatibility of surface-mount IC with a given printed circuit board. In the industrial sector of making and supplying surface-mount integrated circuits, it has been proposed to use a single standard socket accommodating numerous ICs for performance or ageing test. Such a socket however would not be suitable for use with printed circuit boards having different geometric and performance characteristics.